Receptors Flashcards
Who introduced the concept of the receptor?
Paul enrich
What is a receptor?
A macromolecular component of the cell which a drug interacts with to produce a acharacter respon
Receptor properties
Low concentration High affinity or drugs Show selectivity Fully reversible reactions Complementary binding site Antagonist induces conformational change
Assumptions made during equations
Assume law of mass action
Assume negligent amount is bound
Binding is at equilibrium
What is the law of mass action?
Forward rate = K[D][R]
Backwards rate = k-1[DR]
Occupancy to effect theories are?
Occupancy theory and rate theory
What is the occupancy theory?
Number of receptors occupied equal to response
What is the rate theory?
Rate of receptors occupancy equal to response
What is the pD2?
Quantifies affinity of the drug. High pd2 is high potency.
Equation for pd2?
pD2=-log(Kd)
What are antagonists?
Molecules with no outright effect but prevent agonists from having any effect
Types of antagonists?
Competitive and non-competitive
What are competitive antagonists?
Agonist and antagonists bind to the same site, so can block agonist from binding -higher concentrations high effect of blocking
What are non-competitive antagonists?
Bind to a different site on enzyme/receptor and prevent binding of agonist irreversible
How to work out agonist and antagonist affinity?
Kx= [x] [R]/[AR]
X-antagonist/agonist
R-receptor
